No other real context for the photo is provided, and “Rob Mac” isn’t exactly a household name. But when you look through his Instagram feed, it’s a Who’s Who of elite basketball royalty, from Stephen Curry to Kevin Durant, Russell Westbrook to Kevin Love.

McClanaghan was raised in Rhode Island and was a walk-on for Jim Boeheim at Syracuse. Late in a blowout win over Colgate, he was inserted into the game and was told to hold the ball and drain the clock. He sank a three-pointer and defied his to bench him.

After graduating in 2001, he coached briefly in college, then returned to coach high school in Rhode Island. It was there that he was able to ply his trade fully, working with a host of NBA Draft-bound players to hone weaknesses in their games.

In a relatively short amount of time, he became the go-to guy for pre-draft workouts, the doctor to fix broken mechanics, a psychologist to mend bruised egos, and a known and respected commodity in NBA front offices. He explained in a 2013 Yahoo! interview why his approach is so effective:

“You’re going to have four or five different coaches in your NBA career – maybe more – but I’m always staying the same. Every season you’re going to get attention from me. Every summer, you’re going to get it. It’s never going to change. You’re going to get emails and texts and calls from me. I’m watching your games and we’re talking about what you can get better with, what you can add next.

“I’m going to be that consistent person in your life. Your GM isn’t going to fire me. I’m going to grow with you, and you’re going to help me, help you get better.”

John Wall has been working out with Rob Mac since he was introduced via text message in the Spring of 2012. It was McClanaghan who impressed upon Wall the importance of using his speed in varied ways, as well as building confidence in his jump shot.

“It took a long time, took me three years to understand the game more and feel it out better and when you have more confidence and figure out how to use pace,” Wall said in a 2013 Washington Post piece on their relationship. “Everybody has the same plans, but it’s how somebody can make you more confident and more comfortable when you’re working with the same person.”

It doesn’t hurt that he can put in offseason work with James at the same time.